<template>
  <div class="my-tab-bar">
    <div class="tab-item" 
    v-for="(item, index) in arr" 
    :key="index"
    @click="changeTab(index, item.componentName)"
    :class="{current : index === targetIndex }">
      <!-- 图标 -->
      <span class="iconfont" :class="item.iconText"></span>
      <!-- 文字 -->
      <span> {{ item.text }} </span>
    </div>
  </div>
</template>

<script>
export default {
  props: {
    arr: {
      type: Array,
      required: true,
      validator(value) {
        // 如果通过校验就返回true，没通过就返回false
        if (value.length < 2 || value.length > 5) {
          console.error("prop arr\'s length must be  at least 2 and at most 5");
          return false;
        }
        return true
      },
    },
  },
  
  data () {
    return {
      targetIndex: 0 //默认index是0，默认第一个高亮
    }
  },
  methods: {
    changeTab(index, cName) {
      this.targetIndex = index
      this.$emit('changeCom', cName)
    }
  }
};
</script>

<style lang="less" scoped>
.my-tab-bar {
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 50px;
  border-top: 1px solid #ccc;
  display: flex;
  justify-content: space-around;
  align-items: center;
  background-color: white;
  .tab-item {
    display: flex;
    flex-direction: column;
    align-items: center;
  }
}

.current {
  color: #1d7bff;
}
</style>
